After spending the entirety of 1990–91 with the Islanders, the San Jose Sharks claimed him in the 1991 NHL Expansion Draft. During his first season in San Jose, Hackett was named team MVP for his play. However after winning only two games in 1992-93, one of them a Shark record 57 save effort over the Kings, Hackett was dealt to the Chicago Blackhawks prior to 1993–94 and he backed up Ed Belfour for several seasons. His excellent play in 1996–97 allowed the Blackhawks to trade Belfour to Dallas in summer. His only full season as Chicago's top goaltender, 1997–98, was highlighted by a career-high eight shutouts. He remained with Chicago as first choice goaltender until 2004.